docs: def args_fixup():
      """
      Various cleanups/initializations based on result of parse_args().
      """
      global saved_key_handle
      saved_key_handle = args.hmac_kh
  
      args.key_handle = pyhsm.util.key_handle_to_int(args.hmac_kh)
  
      if not (args.mode_otp or args.mode_short_otp or args.mode_totp or args.mode_hotp or args.mode_pwhash):
          my_log_message(args, syslog.LOG_ERR, 'No validation mode enabled')
          sys.exit(1)
  
      global client_ids
      if args.clients_file != None:
          if not args.mode_otp:
              my_log_message(args, syslog.LOG_ERR, 'Clients file should only be used with --otp.')
              sys.exit(1)
          client_ids = load_clients_file(args.clients_file)
          if not client_ids:
              my_log_message(args, syslog.LOG_ERR, 'Failed loading clients file "%s"' % (args.clients_file))
              sys.exit(1)
      else:
          # we accept failure to load this file when the default is used
          loaded_client_ids = load_clients_file(default_clients_file)
          if loaded_client_ids:
              args.clients_file = default_clients_file
              client_ids = loaded_client_ids